1. Field of the Invention
The present invention relates to a dynamic damper structure for controlling vibrations of a vehicle body.
2. Description of Relevant Art
There has conventionally been a problem such that vibrations from a power train are transmitted to a vehicle body through a propeller shaft, axle shafts and upper links.
A particular conventional example will be explained with reference to a rear suspension apparatus shown in FIG. 1 (Structure of Chassis (I), New Edition: Published by Sankaido in 1995). A rear differential apparatus connected to a rear end of an unshown propeller shaft is accommodated in and supported by a rear differential housing 1. Right and left rear axles are connected to both side gears of the rear differential apparatus. The right and left rear axles are accommodated in and supported by rear axle housings 3 integral with the rear differential housing 1. Right and left rear wheel hubs 5 are connected to ends of the right and left rear axles in an interlocking manner. Upper link brackets 7 are mounted on the rear axle housings 3. Each upper link bracket 7 supports one end of an upper link 9 that constitutes a suspension link of which another end is supported relative to a vehicle body. Designated at reference character 11 is a shock absorber, 13 is a coil spring, 15 is a lower control arm, and 17 is a lateral control rod.
The rear axle housing 3 accommodating the rear axle is supported relative to the vehicle body via the upper link 9, lower control arm 15 and lateral control rod 17. Accordingly, when a driving force is transmitted from a power train end through the propeller shaft, rear differential apparatus and rear axle to the rear wheel hub 5, vibrations at the power train end are transmitted from the rear axle housing 3 to the vehicle body, via the upper link bracket 7 and the upper link 9. To this point, an improvement has been desired.
In such the case, a so-called dynamic damper structure may be provided in the rear axle housing 3 and the like. In a peripheral portion of a typical rear axle housing 3, however, there are crowded with many parts such as brake horses so that it is spatially difficult to install a dynamic damper structure.
Further, since the dynamic damper structure has a mass for control, it is required to limit a motion of the mass at a time of rear end collision of the vehicle and the like so as to control effects to the other parts. The provision of a special member results in an unfavorable increase in number of parts.